Comminuting apparatus



Feb. 5, 1963 c. w. SCHMIDT ETAL 3,076,489

COMMINUTING APPARATUS Filed Aug. 10, 1959 '7 Sheets-Sheet 1 T w M H 45 U m n E H c Evsnsrr L.HmmEY Kmws TI! A. H0 Tc m1:

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Feb. 5, 1963 c. w. SCHMIDT ETA].

COMMINUTING APPARATUS 7 Sheets-Sheet 2 Filed Aug. 10, 1959 c. w. SCHMIDT ET Al. 3,076,489

Feb. 5, 1963 COMMINUTING APPARATUS 7 Sheets-Sheet 3 Filed Aug. 10, 1959' ATTY.

Feb. 5, 1963 c. w. SCHMIDT ETAL COMMINUTING APPARATUS 7 Sheets-Sheet 4 Filed Aug. 10, 1959 INVENTORS Cue; 75.4 N. Sen/w m1- [vuzsr L. l-l mvur KsmvsrHA. Hun mus jktVaw/A TY,

Feb. 5, 1963 c. w. SCHMIDT ETAL COMMINUTING APPARATUS 7 Sheets-Sheet 6 Filed Aug. 10, 1959 INVENTORS 1963 c. w. SCHMIDT EI'AL 3,076,489

COMMINUTING APPARATUS 7 Sheets-Sheet 7 Filed Aug. 10, 1959 INVENTORS (flan-'1: M Scan/or [/szerr 1.. Man :1 Know: r1144 Ho 1: n "I:

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Unite States Patent 3,076,489 CQMMINUTENG APPARATUS Chester W; Schmidt, Everett L. Highley, and Kenneth A. Hutchins, Fort Wayne, Ind, assignors to Chemetron Corporation, Chicago, Ill., a corporation of Delaware Filed Aug. 10, 1959, Ser. No. 832,799 16 Claims. (Cl. 146-482) The improved comminuting apparatus comprising the present invention has been designed for use primarily in connection with the comminution and emulsifying of animal foodstuffs and the like, as, for example, noncalciferous parts of certain animals. Such foodstuffs are ordinarily, in themselves, inedible, but when they are so comminuted and emulsified they are converted from a conglomerate mixture into an homogenous mass of a semi-liquid nature and they are thus rendered edible. Of such a character is commercial sausage meat. The invention is, however, capable of other uses and the comminuting apparatus of the present invention may, if desired, with or Without modification, be employed for the comminution of other comestibles, as, for examples, vegetable products or a mixture of vegetable and meat products. Irrespective, however, of the particular use to which the present invention may be put, the essential features thereof are at all times preserved.

The invention is particularly concerned with comminuting apparatus of the type wherein a cutting head having associated therewith a plurality of cutting blades or knives is driven from a suitable source of power such as an electric motor and rotates within a housing in shearing relation to a perforated shear plate, comminuting of the material taking place within the housing on one side of the plate with the comminuted material flowing forwardly through the holes or perforations in the shear plate into a discharge chamber from whence the material passes outwardly through a discharge opening or spout.

It is among the general objects of the present invention, in a machine of the type briefly outlined above, to provide an apparatus of improved design and construction which will more effectively perform its intended function, both as regards the effectiveness of its cutting operation and as regards the volume of the product capable, of being handled by an apparatus of any given size over a given period of machine operation.

Specifically, the objects of the invention are manifold, and principal among them is the provision of a comminuting apparatus of this sort which employs a rotary cutter assembly of improved design, together with novel mounting means therefor whereby the knife blades associated with the assembly will at all times seat squarely against the shearing surface of the shear plate with which the assembly is associated while at the same time the blades are yieldingly urged against the shear plate with a degree of tension that does not vary during the operation of the apparatus. 7

In carryin out the above mentioned objects, and in order to insure equal application of pressure on the shear plate by the shearing edges of the rotary cutting blades or knives at varying radial distances, novel means are provided for reinforcing the shear plate at such radial distances. Accordingly, it is an ancillary object of the invention to provide a novel form of backing spider for the shear plate, which spider, although reinforcing the shear plate by contact therewith at widely separated regions therearound, is so designed as to offer but very little resistance to the passage of the product thcrethrough. By the provision of such a backing spider, the use of shear plates which are of less thickness than conventional shear plates havin the same capacity and designed for the same purpose is made possible.

Another important object of the invention is to provide such an apparatus wherein novel gristle breaking or shear- 3,976,489 Patented ch. 5, i953 ing. means are provided whereby particles or lumps of material which, in conventional apparatus, ordinarily are not severable by the cutter assembly and which, therefore, tend to clog the perforated shear plate, are effectively broken up, ruptured, divided, severed or otherwise softened or partially comminuted so that the thus broken or softened particles are rendered amenable to the shearing action of the cutter assembly against the shear plate.

Briefly, in carrying out this last mentioned object, the invention contemplates the provision of a plurality of wearable, hardened replaceable steel gristle breaking lugs which are secured to the wall of the chamber which encloses the comminuting instrumentalities and which are designed for cooperation with rotary elements on the cut ter assembly to effect the gristle breakin function, such rotary elements being independent from the knife blades proper. By such an arrangement, the gristle breaking functions which, in conventional apparatus, ordinarily are effected by the knife blades proper, are in the present instance effected independently of the knife blades proper so that these blades, as well as the shear plate, will not become overloaded or clogged. Additionally, by an arrangement of this character, the cutting relationship between the gristle breaking lugs and the rotary elements on the cutter assembly which cooperate therewith is maintained constant regardless of cutter blade or knife Wear, or of shear plate wear.

A further important object of the invention, in a machine of this character, is to provide a novel form of cutter assembly having means associated therewith whereby the product which is operated upon by the assembly is automatically impelled forwardly against and through the shear plate under the propelling influence of the cutter assembly itself. In carrying out this object, the invention provides a cutter body or head having cutter blade-supporting arms projecting generally radially outwardly therefrom, each blade-supporting arm presenting a leading product-penetrating cutting edge which extends in the direction of rotation of the blade supported thereby and which is spaced from the shearing face of the shear plate. The knife blade associated with each blade-supporting arm presents a shearing edge which sweeps around the surface of the perforated shear plate and which trails the product penetrating edge of the arm. Immediately behind the leading product-penetrating edge of each arm, and between this edge and the shearing edge of the knife blade, the cutter body is formed with a surface which is inclined with respect to the plane of the perforated shear plate and which exerts a camming or impelling action on the product which has been severed by the leading productpenet'rating edge and tends to force the product forwardly against the face of the perforated shear plate. Stated in other words, the inclined surfaces of the cutter body serve to establish a region of high pressure within the product undergoing comminuting between the blade-supportin arms and the shear plate tending to force the material through the plate perforations into the discharge chamber of the apparatus.

It is another object of the invention to provide a comminuting apparatus of this general character having as sociated therewith means whereby the conglomerate mixmm which comprises the product which is to be comminuted, is introduced into the apparatus in the immediate vicinity of the cutting and shearing instrumentalities so that this mixture is directly and immediately attacked by the rotating knife blades and is quickly moved to the discharge region of the apparatus thereby clearing the way for additional oncoming products. By such an arrangement, the knife blades operate in the open, so to speak, and the building up of j a solid column of the product in the hopper throat preceding the comminuting chamber in advance of the rotating knifeblades is avoided so that the 3 customary feeding of the products under pressure or manual stuffing of the machine is not required.

Yet another object of the invention is to provide a comminuting apparatus wherein the various operative parts thereof are capable of extreme case of assembly and disassembly for purposes of cleaning, inspection of parts, replacement or repair thereof, or substitution of parts to accommodate different kinds of raw product ingredients or to provide comminuted material of different degrees of fineness. In carrying out this object, novel means are provided whereby the feed hopper for the comminuting chamber is movable bodily as a unit toward and away from the comminuting chamber housing, into and out of operative register therewith respectively. When the hop per is in its operative position of register with the housing, the various moving comminuting instrumentalities are concealed and are shielded by the hopper so that contact therewith by the person or clothing of the operator is avoided. When the hopper is in its retracted position out of register with the housing, the various comminuting instrumentalities are exposed to view and are readily accessible for superficial cleaning of the comminuting chamber while at the same time means are made available whereby these instrumentalities may be unlocked so to speak from their normal cooperating positions in the assembly for purposes of dismantling the machine preparatory to a more thorough cleaning of the parts thereof. At the same time, the withdrawn hopper assembly is conveniently accessible for cleaning purposes, both from the feeding end thereof and from the discharge or throat end.

A similar and related object of the invention is to provide a novel assembly of comminuting instrumentalities including the rotary cutter assembly, its cooperating shear plate, a backing spider for the shear plate, and an impeller for centrifugal discharge of the comminuted product from the chamber, these various parts being held in their operative cooperating relationship under the control of a single fastening device in the form of a nut which when unloosened and removed from the assembly, releases the various parts for dismantling. Still further, according to the invention, novel tool means are provided for thus unloosening and removing the fastening nut, as well as for replacing and tightening the same, the tool means constituting an operative and permanent part of the machine and serving, when the nut is removed from its fastening position, to retain the same in a stored position so that the nut will not become misplaced or lost.

In connection with this last mentioned object, an important feature of the invention resides in the provision of means whereby, upon replacing of the fastening nut and tightening of the same to maintain the various comminuting instrumentalities in their operative position, a constant and proper predetermined degree of pressure between the operative shearing elements associated with the cutter assembly cannot be exceeded so that binding of the various parts is avoided while at the same time a uniform shearing effect is attained. More specifically, according to the invention, the fastening nut has associated therewith a tensioning spring which, when the nut is driven to its final home position, is placed under compression in such a manner that an ideal predetermined degree of constant clamping force is applied to the rotary cutter device tending to force the same against the shear plate. The purpose of the fastening nut is not only to maintain the various comminuting instrumentalities in their assembled relationship, but also to exert pressure on the tensioning spring and thus establish the proper degree of pressure between the cutter device and the shear plate. By making it impossible, in the normal application thereof during replacement of the nut after any given dismantling operation, to overtighten the nut, the latter is not relied upon for tension adjustment purposes and the same may be reapplied in position with no particular degree of care being required in the application thereof, and with the certainty that when so reapplied, the necessary and proper degree of tension will be applied to the tensioning spring.

To vary the spring tension and establish diflt'erent degrees of pressure between the cutter device and the shear plate, the use of replacement springs of varying rate, or the use of spacing washers to limit the extent of threaded engagement of the fastening nut on the threaded element to which it is applied may be resorted to.

Another related object is to provide such an actuating tool means for the fastening nut, together with a novel form of safety mechanism whereby, when the tool proper is moved to an operative nut-engaging position, the electric circuit for the driving motor of the apparatus is automatically deenergized so that the power train leading to the cutter drive shaft is disabled and possible injury to the operator is avoided, while at the same time jamming of the machine and damage to the parts thereof is avoided.

Still further, according to the present invention, additional precautionary means are provided whereby, when the feed hopper assembly is moved toward its retracted position out of register with the housing for the comminuting instrumentalities, the motor circuit will be deenergized. By such an arrangement, operation of the exposed cutting instrumentalities during cleaning operations, for example, is made impossible.

Another and important object of the invention, in a comminuting and emulsifying apparatus of the general character set forth above, is to provide a novel form of hopper construction, which construction presents an internal configuration or shape characteristic which is conducive toward free and easy flow of t .e food product ingredients admitted to the comminuting chamber with a minimum of frictional resistance thereto. A related object of the invention is to provide such a hopper construction which is devoid of internal crevi es or pockets and which also is conducive toward easy cleaning thereof,

The provision of a comminuting and emulsifying appuratus which is extremely simple in its construction as compared with machines intended for the same purpose and which, therefore, may be manufactured at a low cost; one which is possessed of a minimum number of relatively moving parts and which, therefore, is unlikely to get out of order; one which is rugged and durable and which, therefore, may be subjected to rough usage; one in which the principal parts thereof are formed of stainless steel so that there will be no oxidation or corrosive contamination of the product; one which is devoid of seams, cracks, crevices and the like in which product particles may collect and which, therefore, is conducive toward case of cleaning; one in which the comminuting chamber thereof is adequately sealed from the atmosphere so that no air or lubricant can be pulled into the chamber; one which is semi-portable in that it is tractionally supported on rails in the vicinity of any given scene of operations so that it may be manually rolled into and out of operative feeding or discharging position; one which is attractive in its ap pearance and pleasing in its design; and one which, otherwise, is well adapted to perform the services required of it, are further desiderata which have been borne in mind in the production and development of the present invention.

Other objects and advantages of the invention, not at this time enumerated, will become readily apparent as the following description ensues.

In the accompanying seven sheets of drawings forming a part of this specification, one exemplary form of the invention has been shown.

In these drawings:

FIG. 1 is a perspective view of an assembled cornminuting apparatus constructed in accordance with the principles of the present invention and showing the same in its operative condition;

FIG. 2 is a perspective view similar to FIG. 1 showing the apparatus in the condition which it assumes when hopper-cleaning operations are in progress;

FIG. 3 is a front end view of the apparatus shown in FIG. 1;

estates FIG. 4 is a fragmentary sectional viewtaken substantially centrally and vertically through the comminuting mechanism proper and the feed hopper therefor and showing the feed hopper in its retracted position;

FIG. 5 is a vertical sectional view taken substantially centrally and longitudinally through the comminuting apparatus and showing the same in its operative condition;

FIG. 6 is an enlarged fragmentary vertical sectional view taken substantially centrally through the apparatus in the vicinity of the comminuting chamber and showing the adjacent base portion of the feed hopper therefor;

FIG. 6a is a reduced sectional view taken substantially along the line 6a6a of FIG. 6;

FIG. 6 is a reduced sectional view taken substantially along the line 6b-6b of FIG. 6;

FIG. 7 is a fragmentary quarter section view on an enlarged scale taken substantially along the line 7-7 of FIG. 6;

FIG. 7a is a sectional view on a further enlarged scale taken substantially along the line 7a--7a of FIG. 7;

FIG. 8 is a sectional view on an enlarged scale taken substantially along the line 88 of FIG. 6;

FIG. 9 is a sectional view on an enlarged scale taken substantially along the line 99 of FIG. 6;

FIG. 10 is a side elevational view of a cutter assembly employed in connection with the present invention;

FIG. 10a is a sectional view taken substantially along the line 19d10l1 of FIG. 9;

FIG. 10b is a sectional view taken substantially along the line 10b10b of FIG. 9;

FIG. 11 is an enlarged fragmentary sectional view taken substantially along the line 1111 of FIG. 6;

FIG. 12 is an enlarged fragmentary vertical sectional view taken vertically and substantially centrally through a position of the apparatus in the vicinity of a capstan tool employed in connection with the present invention and showing the same operatively embracing and retaining a tensioning nut also forming an element of the invention;

FIG. 13 is a fragmentary detail view of an electrical switch box and its associated switch mechanism employed in connection with the invention;

FIG. 14 is a circuit diagram illustrating the operation of certain circuit breaking mechanism employed in connection with the invention; and

FIG. 15 is an enlarged detail view of a portion of the structure shown in FIG. 6 in the vicinity of a rotary mechanical seal employed in connection with the invention.

BRIEF DESCRIPTION AND GENERAL CONSIDERATIONS dumped or otherwise fed to the feed hopper associated with the apparatus. Accordingly, the apparatus may be tractionally supported on a pair of rails 12 leading to a given scene of operation, the apparatus including a base plate 14 adjustably supported as at 16 (FIG. 5) on flanged traction wheels 18 adapted to travel on the rails 12. A

chock member 20 is welded to one of the rails 12 and may be employed for limiting the extent of linear tractional movement of the apparatus in opposite directions into and out of operating position.

Briefly, the apparatus It) involves in its general organization five principal assemblies including a comminuting and emulsifying apparatus proper 22, a feed hopper assembly 24 for the apparatus 22, a combined motor support and manipulating tool assembly 26, a motor assembly 28 and a power train assembly 30 operatively connected between the motor assembly and the comminuting assembly proper 22. The comminuting assembly proper 22 includes a generally cylindrical composite housing 32 providing, in combination with a portion of the feed hopper assembly, an internal enclosure or chamber 34 (see also FIG. 6) which serves to enclose the operative comminuting instrumentalities' associated with the present apparatus. The feed hopper assembly 24 includes a feed hopper proper 36 which is slidable on a base support 38 toward and away from the housing 32 and into and out of operative register with the latter. When the hopper 36 is in its advanced position of registry with the housing 32, product materials loaded into the hopper will be fed to the com rninuting instrumentalities within the forward region 34a of the chamber 34, comminuted thereby, and discharged from the rear region 34b of the chamber through a discharge conduit 40. When the feed hopper 36 is in its retracted position as shown in FIG. 2, it is out of operative register with the housing 32, and the hopper itself, as well as the comminuting instrumentalities, or at least certain of them, are accessible for inspection or cleaning purposes, as will be made more clear presently. Movement of the hopper toward and away from the housing 32 is manually effected under the control of a toggle joint mechanism which has been designated in its entirety at 42.

As best seen in FIG. 5, the feed hopper assembly 24, the power train assembly 30 and the motor supporting and tool retaining assembly 26 are disposed in longitudinal alignment on the base plate 14. The feed hopper assembly 24 has associated therewith a certain safety control mechanism which, as will be more clearly set forth presently, is operable under the control of a thrust rod 44 (FIGS. 2, 4 and 5) capable of being shifted axially in one direction when the feed hopper 36 is moved away from its operative position to actuate a certain circuit breaking mechanism subsequently to be described and disposed in the motor circuit associated with the motor assembly 28 and to deenergize such circuit so that operation of the motor, and consequently of the comminuting instrumentalities within the chamber 34 is prevented when the feed hopper is in a position other than its operative position.

The comminuting and emulsifying instrumentalities which are disposed within the chamber 34 includes a rotary cutter assembly 50, a perforated shear plate 52, a backing spider 54 for the shear plate 52 and an impeller 56 by means of which the comminuted and emulsified material is centrifugally discharged from the chamber 34 through the discharge conduit, 4t). The cutter assembly 50 and impeller 56 are operatively disposed on a tubular rotary drive shaft 58 having an axial bore 59 through which there extends a clamping rod or shaft 60 which is held in its clamping position by mechanism including a nut 62 adjacent its rear end. When the nut 62 is unfastened from the rod 60, the latter is released for removalpurposes, together with the various operative comminuting instrumentalities clamped thereby.

While it is possible to unfasten the nut 62 by conventional means such as a hand wrench or the like, according to the present invention it is contemplated that this nut shall be manipulated only under the control of a built-in tool unit 64 in the form of a permanently mounted rotary capstan wrench carried on a rotatable and axially slidable shaft 66 which constitutes an element of the combined motor support and tool retaining assembly as. The tool unit 64 and tool shaft 66 are axially aligned with the nut 62 and are movable between an advanced position wherein the tool unit engages the nut and a retracted position wherein the tool is remote from the nut. The tool shaft 66 cooperates with an additional circuit breaking mechanism to open the motor circuit whenever the tool assembly is withdrawn from 7. its normally inoperative retracted position, as will be made clear presently. Thus, as a precautionary measure, the driving motor for the apparatus cannot be set into operation during nut-manipulating operations.

THE COMMINUTING ASSEMBLY PROPER The Housing Assembly Referring now to FIGS. and 6, the housing 32 is of a two-piece sectional composite nature and includes a for ward casing section 7t which provides the previously mentioned internal chamber 34 and a rear casing section 7?; providing an internal lubricant reservoir 74 having a conventional air vent '75 associated therewith. The casing section 72 is of generally open-ended tubular construction and has a front end flange '76 and front and rear foot portions 78 and 80 respectively by means of which the section '72 is secured to the base plate 14, suitable fastening bolts 82 being provided for this purpose. The front casing section '79 is of cup-shape design and presents a radially extending rear wall 3 having a rearwardly projecting peripheral rim flange 36 which is clamped against the bolting flange Fri by means of suitable clamping bolts 88. The wall 8 is in the form of an annulus having a central opening 90 therethrough and a rearwardly projecting inner peripheral wall 92 which is telescopically received within the generally cylindrical casing section 72. The wall 92 carries a sealing ring 94 which may be in the form or" a conventional O-ring and by means of which the lubricant chamber or reservoir 74 is sealed against egress radially to the atmosphere between the two casing sections 7 6' and 72.

The forward end of the cup-shaped casing section 70 is open and provides a forwardly projecting rim 96 adapted to fit telescopically within an annular recess 98 provided in the rim region 99 of a hopper throat 1% associated with the hopper assembly 24. An O-ring seal 162 between the two telescopic rim regions insures a separable but tight leak-proof seal between the casing section 76 and hopper throat me when the hopper assembly 24 is in its advanced position.

The Cutter Drive Shaft and Mounting Therefor Still referring to FIGS. 5 and 6, the tubular rotary cutter drive shaft 58 extends axially through both casing sections 7t? and 72 and is rotatably journalled in anti-friction bearings H2 and 1.14 interposed between the shaft and casing section '72 adjacent the front and rear ends of the latter respectively. The shaft 58 projects a slight distance forwardly of the rim 96 of the casing section '70 and it projeots an appreciably greater distance rearwardly of the section '72, the rearwardly projecting portion thereof serving to carry a pulley 3.16 which constitutes the driven 1 ember or output pulley of the power train assembly 3%. The level of lubricant maintained within the reservoir 74 may be maintained substantially constant by means of a conventional lubricant feed reservoir assembly which has been designated in its entirety at 117, the level of lubricant maintained in the reservoir preferably being such that the outer bearing race of the anti-friction bearing assembly 112 extends below the surface of the pool of oil contained within the reservoir 74 as indicated by the dotted lines in FIG. 6.

The rear end region of the drive shaft 5% projects outwardly from the lubricant chamber 74 through an end closure member 118 which is secured by screws 12% in position over the rear open end of the casing section 72. A lip type seal 122 serves to prevent egress of lubricant from the reservoir or chamber 74 to the atmosphere through the annulus existing between the closure member 118 and the drive shaft 58.

The central bore 59 provided in the tubular cutter drive shaft 58 is coextensive with the shaft. The previously mentioned clamping rod 6t) extends completely through the bore 124 and forms an element of a releasable clamping assembly by means of which the various comminuting &

instrumentalities including the cutter assembly 50, the shear plate 52, the backing spider 5d and the impeller 56 may be operatively maintained in their respective operative positions within the chamber 34. The nature and function of the clamping rod 66 will become clear presently when the character of the various operative comminutin g instrumentalities has been set forth.

The tubular cutter drive shaft 58 is of stepped configuration, the medial region 126 thereof, i.e., the region which is disposed within the lubricant chamber 74, being of relatively large diameter with successive diameter reductions being effected on opposite sides of the enlarged medial region. On the forward side of the enlarged medial region 126, three such progressively decreasing stepped regions 123, 13% and 132 are provided, while on the rear side of the medial region 126, two such progressively decreasing stepped regions 136, 138 are provided.

The region 128 is supported by the bearing assembly 132 and the inner race 140 of the assembly 112 is adapted to be clamped against the shoulder 142 existing between the regions 1% and 128 by means of a nut 144 which is threadedly received on a threaded section 146 of the region 328.

The region 130 projects through the central opening 90 provided in the rear wall 84 of the casing section 70 and an end-face seal assembly which is designated in its entirety at 148 serves to seal the annulus existing between the cylindrical surface of the region 139 and the cylindrical surface of the opening 90. The end-face seal 148 is of the type wherein a gas and liquid tight joint is effected between two running seal faces which are lapped to a high degree of flatness on the order of one and one-half times the wave length of light. While various forms of endface seals are suitable for sealing the chambers 34 and 74 from each other, the particular seal employed herein includes a member 156 in the form of a ring commonly known by seal rnanaufacturcrs as a seat and which is secured to the wall 84 by means of fastening screws 151. The seal seat projects radially inwardly of the opening 98 and is sealed to the wall 84 by means of an O-ring seal 152.

The rear face of the seat member 15s as shown in FIG. 15 is formed with an enlarged threaded counterbore 149 which threadedly receives therein a retaining ring 3"3 having an undercut groove providing a thin annular tongue 157 which extends into an annular groove 159 provided in an elastomeric sealing ring 161. The ring 161 is formed with an internal flexible sealing lip 163 which is compressed between the tongue 157 and the rotatablc shaft 58 and is in sealing relationship with respect to the latter. The retaining ring 153 serves to compress the sealing ring 161 against the shoulder 165 afforded by the counterbore 149. This lip sealing ring 161, in combination with the spring-loaded sealing washer 158 insures that no product enters the bearings and lubricating chamher, and that atmosphere and oil from the lubricating chamber are likewise excluded from the product. The seat 1559 presents a rearwardly facing fiat sealing annulus 154. designed for running sealing engagement with a similarly fiat sealing annulus 156 provided on a sealing ring 158 commonly known as a sealing washer. The seat 150 and Washer 153 may be formed of various materials commonly employed in the construction of end-face seals, cast iron being one such material. "he washer 153 is axially slidable on the shaft 53 and is rotatable with the shaft through the medium of a brass or other metal retainer tea which is pressed onto the region 130 and which has a lost motion driving connection with the seal washer. A spring 162 surrounds the retainer and normally urges the washer against the seat so as to compensate for wear between the parts. An elastomeric sleeve 164 surrounds the spring 162 and is cemented or otherwise secured to the washer 158 at its forward end and is similarly secured to the retainer 166 at its rear end.

The region 132 constitutes the end of the tubular shaft 58 and it is non-circular in cross section. Preferably it is provided with a series of longitudinally extending splines 166 which receive tliereover the internally splined impeller 56. The region 132 projects at least partially through the backing plate 54 for the cutter assembly 50 and the extreme end of the shaft projects into a splined recess or socket 168 formed in the hub portion 170- of the cutter assembly 50. The cutter assembly is thus rotatable with the drive shaft 58 and it is capable of limited axial sliding movement therealong, the clamping rod 60 serving to normally urge the cutter assembly rearwardly in the chamber 34 and against the shear plate 52 inoperative shearing relationship therewith in a manner and by mechanism that also will become clear as the following description ensues.

The Shear Plate and its Mozmting Referring now to FIGS. 6, 9 and 11, the shear plate 52 is in the form of a flat circular perforated disc, the rear face of which is yieldingly clamped against the forward face of the backing spider 54,- with both the shear plate 52 and the spider 54 extending vertically across the chamber 34 adjacent the extreme forward region of the latter and near the rim 96 of the casing 70'. The shear plate 52 is of annular design and the internal diameter thereof is substantially equal to the external diameter of the hub 170, thus providing a central opening 172 in the plate through which the hub 170 projects with a fairly close fit and within which opening the hub 170 is adapted to rotate. The shear plate 52 has a narrow solid inner peripheral hub portion 174 and a similarly narrow outer peripheral solid rim portion 176 with an intervening perforated annulus. Between the hub portion 174 and rim portion 176, the annulus 52 is drilled to provide a series of shear holes 178, the number of which will control the fineness of the comminuted product. The number of holes employed and the specific hole pattern may vary in wide limits. In an exemplary form of the invention where a shear plate having a drilled annulus of approximately 9 /2 inches external diameter and 5 /8 inches internal diameter, satisfactory results will be obtained with shear holes ranging from 1000 to 10,000 in number. In accordance with conventional practice, one or more interlocking pairs of keys and recesses 180,- 182 respectively are provided on the casing 70 and in the periphery of the shear plate 52 to prevent turning movement of the shear plate within the chamber 34.

The Backing Spider As shown in FIGS. 6 and 7, the backing spider 54 is of ring-like design and includes an inner circular hub portion 190, an outer peripheral circular rim portion 192 and a series of interconnecting radial webs or spokes 194 which are equally spaced from each other circumferentially. While any number of such spokes may be provided, in the illustrated form of the invention, eight such spokes extend in diverging fashion at an angle of 45 from each other. The spider 54 fits loosely within the cylindrical wall of the chamber 34 and the rear face of the rim portion 122 seats on a shoulder 196, and against which shoulder the spider is yieldingly urged under the influence of the axial thrust of the cutter assembly 50 which bears against the shear plate 52 and in turn forces the latter against the backing spider 54. The keys 130 on the casing 70 extend int-o notches 193 provided in the spider and thus the spider is maintained against turning movement within the chamber 34.

The circular hub 190 and circular rim 192, in combination with the radial webs 19d, define a series of eight generally trapezoidal openings 200 through which the product issuing from the shear plate 52 is adapted to pass rearwardly. The forward sides of the various spokes 194, as well as of the hub 190 and rim 19 2, are bevelled as at 202 on a relatively sharp angle as best seen in FIG. 7a to enhance the movement of the product rearwardly through the spider toward the rear regions of the chamber 34 where it is operated upon by the impeller 56 and discharged from the chamber 34 through the discharge conduit 40 in a manner that will be made clear presently. The webs we are thus generally triangular in transverse cross section and present thin linear edges 203 which, in their radial extent across the forward face of the shear plate, intersect only a relatively few of the shear plate openings. Because of the fact that the backing spider 54 reinforces the shear plate 52 at varying radial distances, the use of a relatively thin shear plate may be resorted to, without resulting in deflection or rearward bowing of the shearplate. Additionally, because little friction is developed during passage of the product through the spider, undue internal temperatures which otherwise would be created under the influence of friction are avoided.

The Cutter Assembly Referring now to FIGS. 6, 9 and 10, the cutter assembly 50 involves in its general organization a cutter body or head 210 in the form of a three-arm spider or blade support, the central hub portion 170 of which presents a generally cylindrical surface 214 and a rear frustoconical surface 216. The cylindrical surf-ace 214 fits telescopically and slidably within the hub 174 of the shear plate 52. The previously mentioned splined socket 168 is telescopically received over the splined end region 132 of the tubular drive shaft 58. Formed on the hub portion 212 of the cutter body 210 are a series of three radial knife-supporting arms 218. These arms diverge radially from one another at angles of 120 with the individual arms being inclined forwardly in the rotary direction of lead of the impeller assembly as indicated by the arrow in FIG. 9. The trailing sides 220 of the arms extend substantially tangential to the cylindrical surface 214 of the hub 210 while the leading faces 222 of the arms extend substantially truly radially of the hub 210 as best seen in FIG. 9. The underneath faces 224 of the arms 218, as viewed in FIG. 10, lie substantially in a common plane while the forward leading faces of the arms are undercut and extend forwardly and upwardly and terminate in sharp product-penetrating edges 228. The outer or distal end faces 225 of the arms 218 are curved and, in combination with the leading faces 222, define relatively sharp shearing edges 226 designed for shearing cooperation with a series of gristle shearing lugs 227 carried on the radial wall of cutting chamber 34a located in rim 99 at the outlet end of throat member 100 and the nature of which will be set forth presently. The underneath face 224 of each arm is formed with a generally radially extending groove 229, the planar extension of which passes in secant fashion through the hub 210 and within each groove 229 is secured as by furnace brazing a knife blade proper 230 in the form of a hardened steel plate which projects outwardly beyond the face 224 and is provided with -a sharp cutting or shearing edge 232 adapted to sweep around the forward face of the shear plate 52 in the usual manner of shearing cooperation between the knife blades and shear plates of conventional rotary cutters.

The Cutter Biasz'ng Mechanism As previously stated, means are provided for norm-ally biasing the entire cutter assembly 50 to the right as viewed in FIG. 6 to bring the shearing edges 232 of the various knife blades 230 into shearing contact with the forward face of the shear plate 52. Accordingly, as best seen in FIGS. 5 and 6 the forward end region of the clamping rod 60 projects forwardly beyond the end of the splined region 132 of the tubular drive shaft 58 and extends into a socket or recess 234 provided in the cutter hub 17%. The extreme end of the rod terminates in the general plane of the rim of the socket. This projecting end of the rod 60 is formed with an annular groove 236 adapted to receive therein asplit retainer 238 of the half-moon variety, the retainer nesting within the socket 234 when l l. the various parts are in their operative position. The portion of the rod 60 which passes through the splined section 132 of the shaft 58 is sealed to the bore of the shaft by Cr-ring seals 239 as best seen in H6. 6.

As previously stated, the rear end region of the tubular drive shaft 58 projects rearwardly of the closure member 118 and carries the pulley 116. This rear end region of the shaft 53 terminates within an axial bore 241 formed in the pulley 116 while the rear end region of the rod 6% projects outwardly beyond the rear end of the tubular drive shaft and beyond the rear end of the pulley 116 and has its extreme rear end region threaded as at 2 52 (FIGS. 4 and 5) for reception thereover of the nut 62. A helical compression spring 243 is disposed within the annular space existing between the rod so and the wall of the bore 241 and bears at its forward end against the extreme rear end of the tubular drive shaft 58 and at its rear end against the nut 62. The spring 243 thus normally urges the clamping rod 60 axially to the rig t as viewed in FIGS. 5 and 6 and this rod, being slidable within the bore 59 of the drive shaft, thus normally pulls the entire cutter assembly 50 toward the shear plate 52 as previously described. In order to prevent turning of the clamping rod 60 within the bore 59, a longitudinally extending groove 23.; (FIG. 5) is formed in the rod 60 and slidably receives therein the inner end of a screw 237 which is radially and threadedly received through the wall of the tubular drive shaft 58.

In order that the three knife blades 230 shall seat squarely upon the forward face of the shear plate 52 at all times, with no possibility of separation therefrom due to misalignment of the parts, the splined region 13% of the drive shaft 58 does not have a tight fit within the splined recess 1655 (FIG. 9) and thus the cutter hub 210 is cap-able of limited universal movement on the extreme forward end of the shaft 58. By the term limited universal movement as used herein, is meant the amount of play or wobble permitted between the splined region 166 of the drive shaft 58 and the splined recess 168 of the hub by virtue of the slightly loose or non-tight fit of the referred to splined parts. Since, geometrically speaking, any three points in space define a common plane, and since only three knife blades are employed herein, it is obvious that each of the knife blades will at all times be firmly yet evenly drawn into operative engagement with the forward operative shearing face of the shear plate 52. By regulating the degree of compressional force applied to the spring 243 by the nut 62, a constant tension may be applied on the cutter assembly.

The Centrifugal Impeller The impeller 56 is best illustrated in FIGS. 6 and 8 and is in the form of a three-bladed spider-like body having a central hub region 244 which merges gradually with a series of three radially diverging tapering expeller arms or blades 245. The impeller body is of uniform thickness throughout, its thickness being appreciably great to enhance its effectiveness in centrifugally expelling the comminuted material which has passed through the shear plate 52 and spider 54 from the chamber 34.

The hub region 244 is formed with a central splined opening 246 therethrough by means of which the impeller is splined to the region 132 of the tubular drive shaft 58. The impeller is prevented from engaging the rear face of the spider 54 during initial assembly operations and it is maintained out of contact with the spider during operation of the apparatus by means of a series of three nylon, Teflon or other anti-friction plugs 247 having long wear properties and which are set into sockets 24-8 which are drilled in the forward face of the expeller arms 245. The outer ends of these anti-friction plugs are adapted to frictionally engage and slide upon the rear face of the narrow hub portion 199 of the backing spider 54.

The discharge conduit 4% communicates with the chami2 ber 3 through a product discharge opening 24? formed in the wall of the chamber 34 in the side regions of the latter. The opening 241 communicates with the lower end of the inclined discharge chute 40.

The Gristle Breaking Instrumentalities The comrninuting and emulsifying instrumentalities of the present invention have associated therewith gristle severing means whereby any tendons, ligaments, small bone nodules and other forms of gristle may be reduced in size by a shearing action which is effected between the various knife-supporting arms 213 and a. series of four of the previously mentioned gristle shearing or breaking lugs 227 (FIGS. 6 and 9).

These gristle shearing or breaking lugs 227 are in the form of hardened steel blocks which are square in cross section and which are formed with cylindrical shank portions 227a which extend through radial bores 253 formed in the wall of the cutting chamber 34a located in rim 99 at the outlet end of throat 168 at regions which are circumferentially spaced apart. The outer ends of the shank portions 227:: are threaded as at 255 and receive thereover fastening nuts 25? which are accessible exteriorly of the casing for replacement of the lugs 227 when desired. The shank portion 227:: of each lugs 227 is sealed to the wall of cutting chamber 34a located in rim 9 by means of an O-ring 259. The various lugs proper 227 seat within shallow square recesses 261, as best eon in FIG. 9, and thus, by loosening of the various nuts 257, the positions of the lugs 22-7 may be adjusted by turning the lugs about the axes of the various lug shanks throughout angles of 90 to present any one of the four shearing edges associated with the lugs counter to the direction of sweeping movement of the knife-supporting arms 218. Upon rotation of the cutter assembly 59 in the direction of the arrow in FIG. 9, the arcuate faces 225 of the knife blade-supporting arms 218 sweep within the chamber 34a in the rim 99 of the hopper throat 16:) in close proximity to the planar inside faces of the lugs 22.7 so that the leading edges 226 of the arcuate faces 225 serve to break, fracture or shear any particles of gristle which they may encounter as they move across the lugs 2-27.

THE FEED HOPPER ASSEMBLY Referring now to FIGS. 1, 3 and 5, the feed hopper assembly 24 is slidable toward and away from the composite housing 32 between the operative advanced position of the assembly and the retracted position thereof respectively and, in so sliding, the assembly 24 is guided on a pair of guide rods 25%, 251, these rods being supported in spaced parallel relationship above the level of the base plate 14 by means of standards 252. The hopper proper 36 is in the form of a stainless steel shell of generally conical design having a slant angle in the neighborhood of approximately 45 the cone bein inverted and having the small base or rim thereof welded as at 254 to the open upper end of the hopper throat member 100. The hopper shell 36 is maintained in its inverted position by means of supporting struts 256 which extend between the upper regions of the shell and a pair of guide sleeves 25S slidably disposed on the guide rods 250 respectively. A fiat web 269 extends between the two sleeves 258, is integral therewith, and may be integrally formed with the throat member 1% if desired. The lower open end of the throat member 100 is adapted to communicate through the web 269 with the forward open end of the casing section 70 when the hopper assembly is in its operative assembled position on the housing 22. A tubular strut extends horizontally between the two sleeves 258 and, in addition to its reinforcing function, serves as a limit stop for determining the home position of certain toggle mechanism, the nature and function of which will be set forth presently. To prevent swirling of the material fed to the hopper, a series of raised veins or ribs 273 are formed internally of the hopper throat 100.

Referring now to FIGS. 5, 6, 6a and 6b, it will be seen that a tangent line extending along the generally frustoconical hopper assembly including both the hopper proper 36 and the hopper throat 100 at the rear side of the hopperis substantially linearly straight (FIG. with the line being inclined relative to a horizontal plane at an angle of approximately 45. The net eifect of this shape phenomena is to provide a linear ramp in the form of a curved wall trough having a slant angle which is appreciably greater than the angle of repose at which product particles will fail to slide freely along the ramp. In other words, this ramp portion of the hopper assembly is sufiiciently steep as to insure movement of the product therealong without obstruction. The throat portion 100 of the hopper presents an internal surface which, as shown in FIGS. 6 and 6a, is truly circular in horizontal cross section and which, as shown in FIG. 6b, is elliptical in transverse cross section, i.e., in a plane extending at a right angle to the inclined central axis of the hopper throat 100. The minor axis of the ellipse extends across the hopper throat as indicated by the dotted line 263 in FIG. 6 while the major axis extends at a right angle to the minor axis horizontally across the hopper throat. In vertical cross section as indicated by the dotted line 265 in FIG. 6, the cross sectional contour of the hopper throat is circular so that the forwardly facing throat opening which is in register with the forward open rim of the casing section 70 is circular.

Manually operable means are provided for shifting the hopper assembly 36 between its advanced and retracted positions, such means being in the form of the previously mentioned toggle mechanism which has been designated in its entirety at 42 (FIGS. 1 and 6). The toggle mechanism 42 includes a pair of toggle links including a dual link assembly 264 consisting of parallel link bars connected at their rear ends to a cross pin 266 carried at the outer end of a threaded rod 268, the inner end of the rod being threadedly received as at 270 in the socket 272 (FIG. 5) provided in a boss 274 formed on the side wall of the hopper throat 100. A nut and washer assembly 276 serves to lock the threaded rod 268 in any selected position of axial adjustment within the socket 272. The forward ends of the parallel links 264 are connected by a cross pin 278 to a second toggle link 280, this latter link constituting one leg of a bell crank lever 282, the other leg of the lever being in the form of an operating arm 284 provided with a manipulating handle 286 at its upper end. The base or bight of the bell crank lever 282 is pivoted on a pin 288 which extends between a pair of ears 290 integrally formed on the forward standard 252.

As previously stated, the hopper assembly 36 is movable between the advanced operative position wherein it is shown in FIG. 1 and the retracted inoperative position wherein it is shown in FIG. 2. When the hopper assembly 36 is in its advanced position, the operating lever 284 assumes a forwardly and upwardly inclined position as shown in FIG. 1 with the toggle links 280, 264 extending in substantial alignment but just over toggle dead center. With the toggle links thus positioned, maximum toggle length is attained and, by virtue of the adjustment of the nut 276, the extreme forward rim 96 of the casing 70 and the bottom wall of the recess 98 provided on the hopper throat 100 are forced into firm sealing engagement. To prevent breaking of the toggle links 280, 264, the lower edge 291 of the toggle link 264 is designed for engagement with the tubular strut 165. A rectangular slot 292 is provided. in the standard 252 and within this slot the bell. crank lever 282 is adapted to operate.

In order to move the hopper assembly to its retracted position as shown in FIG. 4, it is merely necessary to pull the handle 286 rearwardly so that the bell crank lever 282 assumes the position wherein it is shown in this figure whereupon the toggle links 280, 264 will be broken and the feed hopper assembly 24 will be moved to its retracted position with the guide sleeves 258 assuming positions on the guide rods 250 near the forward end thereof. In this position of the hopper assembly 24, the forward open end of the casing section 70 is accessible and the cutter assembly 50 is in full view. The movement of the hopper assembly 24 to its retracted position may be effected incident to this assembly of the various cutting instrumentalities in a manner that will be described subsequently.

THE DRIVING MOTOR AND POWER TRAIN ASSEMBLY The motor assembly 28 includes a motor base plate 300 (FIGS. 1 and 5) having a pair of depending lugs 302 adjacent each end thereof and by means of which the base plate is supported on a pair of supporting shafts 304 which extend through the lugs 302 at each end of the base plate and are themselves carried in upstanding supporting ears 306 formed on the upper face of a flat horizontal table portion 308 associated with an inverted boxlike casting 310 which constitutes the stationary framework of the previously mentioned motor support and toolretaining assembly 26. The base plate 300 thus is supported in an elevated position above this latter assembly and a driving motor M is bolted as at 312 in position on the base plate. The motor M is of conventional design and it is provided with a motor shaft 314 on which there is disposed a driving pulley 316 of the multiple groove type. The previously mentioned driven pulley 116 of the power train assembly 30 which is mounted on the tubular drive shaft 58 is also of the multiple groove type and a series of driving belts 318 extend over the two pulleys 316 and 116 in driving relationship. It will be noted that the pulley 116 has a rearwardly extending annular portion which circumscribes the spring 243 for predetermining the extent to which the tool socket of the tool assembly may engage the nut 62 to limit the amount the spring 243 may be compressed or tensioned. The belt and pulley assembly 316, 318, 116 is enclosed in a sheet metal casing 320 suitably mounted on the base plate 14, the casing affording a protective cover for the driving mechanism. Suitable set screws 322 and 324 serve to anchor the pulleys 316 and 116 respectively in vertical alignment on their respective shafts 314 and 58. The sheet metal casing 320 may be stabilized by a connecting strap 326 which extends between the rear wall of the casing and the front side surface of the base plate 300.

THE TOOL RETAINING ASSEMBLY The combined motor support and tool retaining assembly 26 is best seen in FIGS. 1, 2 and 5. This assembly has as its principal component the previously mentioned inverted box-like casting 310 which provides the table support 308 for the motor base plate 300 as previously described. The table support 308 is carried on a pair of side members 350 and 352 which may be bolted as at 354 to the base plate 14. The tool unit or wrench 64 is in the form of a capstan wheel having a central hub 356 from which there extends radially a series of operating bars 358. The hub is provided with an axial bore 360 into which bore the forward end of the previously mentioned wrench shaft 66 extends and in which it is pinned as at 362. As will be explained presently, the wrench shaft 66 serves a dual function of rotatably supporting the capstan wrench on the casting 310 and of actuating. certain limit switch instrumentalities, the nature and function of which will be set forth presently. The shaft 66 is rotatable and axially slidable in an elongated bore 364 formed in the table portion 308 and normally the shaft 66 is maintained in the retracted position in which it is shown in FIG. 5 by means of a spring pressed detent 366 which registers with an annular groove 368 provided in the shaft 66. The shaft 66 and capstan wrench 64 carried thereby are shiftable bodily as a unit forwardly of the casting 310 to bring the wrench 64 into operative register and engagement with the nut 62 carried on the rear end of the clamping rod 69 in order that the Wrench may be employed for nut loosening and removal purposes. Accordingly, the shaft 66 and wrench 64 are in axial alignment with the rod of} and the hub 356 of the wrench 64 is formed with a socket 370 (see also FIG. 12) the configuration of the socket conforming to that of the nut 52., such configuration preferably being square, although other non-circular configurations are contemplated. Each side face of the nut 62 is formed with a socket 3'72 therein, the various sockets being designed for selective register with the inner end of a spring-pressed plunger which extends through one side wall of the socket 379 and which is slidable in a bore 376 provided in an upstanding boss 378 formed on the hub 356. The plunger 37 2- is provided with a stem 3% which projects outwardly through a plug 381 threadedly received within the bore 376 and a compression spring 382 surrounds the stem 389 and bears at one end against the plug 381 and at its other end against the shoulder 384 which exists between the plunger 3'74 and its stern 380. It will be seen, therefore, that the plunger 374 is at all times yieldingly urged to an advanced position wherein the inner end thereof projects into the socket 370. A lifting bail 386 is carried at the outer end of the stern 380.

From the above description, it will be seen that in order to loosen and remove the nut 62 from the threaded end Ld-i of the rod 60, the capstan wrench 54 may manually be pulled forwardly while at the same time the bail 386 may be manipulated to lift the plunger and withdraw the end thereof from the socket 376 so that the socket may be telescopically received over the nut 62 in the manner indicated in FIG. 4. Upon release of the bail 386 the end of the plunger 374 will drop into one of the holes 3'72 provided in the side faces of the nut 62 so that the nut will be captured, so to speak, by the capstan wrench 64-. The wrench may then be turned to loosen and ultimately remove the nut 62 from the rod 60 after which the capstan wrench and the shaft 66 on which it is mounted may he slid rearwardly to their retracted positions wherein the detent 365 seats within the groove 368. The not 62 will remain within the socket 370 thus preventing possible misplacement or loss of the nut while at the same time maintaining the nut in a convenient position of alignment with the threaded end of the rod 69 for ready reapplication to the rod 60 after assembly of the various comminuting instrumentalities associated with the housing 32 has been completed.

THE MOTOR DEENERGIZING SAFETY MECHANlSM As previously stated, means are provided for deenergizing the electrical circuit for the motor M when either the capstan Wrench 64 is moved from its normally inoperative or retracted position or when the hopper as sembly 24 is moved from its operative position of registry with the casing section 76.

Accordingly, as best seen in FIGS. 4 and 5, the thrust rod 4-?- extends from the vicinity of the forward rim 95 of the casing 70, rearwardly past the entire housing assembly 32, through the sheet metal casing 320 of the power train assembly 36, through the side members 359 and 352 of the inverted box-like casting 31d and into a chamber see (see also FIG. 13) afforded on the rear face of the side member 352 by virtue of a sheet metal boxlike structure 4412 suitably secured to the casting. The rear end of the rod 44 is designed for camming engagement with the actuating finger 404 of a microswitch M81 secured by screws 4% to the side member 352. As shown in FIG. 14, the microswitch M81 is of the normally open type and includes a pair of normally open contacts C1 which disposed in the electric circuit for the motor M lid and which are adapted to become closed when the actuating finger 4% associated therewith is engaged by the end of the rod ed as shown in dotted lines.

Similarly, as best seen in FIGS. 5 and 13, the axially slidable shaft 66 projects through the side member 352 and into the chamber 469 where the extreme rear end region thereof cooperates with the actuating finger 403 (FIG. 14) of a mi roswitch M82 secured by screws 406 to the side member 352. The microswitch M82 is also of the normally open type and includes a pair of normally open contacts C2 (FIG. 14) which are disposed in the motor circuit of the motor M and which are adapted to become closed when the end region of the shaft 66 is withdrawn from contact with the actuating finger 408. it is to be noted at this point that the box-like structure which encloses the microswitches MS]. and M32 has a front wall 412 which conceals these electrical instrumentalities and which presents a void or opening 414 at the bottom of the structure for the drainage of any condensate or other moisture from the interior of the structure.

The Circuit Diagram Referring now to the circuit diagram of FIG. 14, upon closure of a manual circuit breaker of any well-known type, such as the master switch MS, the electric circuit for the motor M will become energized. This circuit extends from the positive side see of the power line through lead 501, the motor M, lead 502, normally closed contacts C2 of the microswitch M32, lead 503, normally closed contacts C1 of the microswitch M31, and lead 504 to the negaive side 535 of the line. The motor will normally remain energized as long as the master switch MS remains closed. However, at such time as either pair of contacts C1 or C2 becomes open due to removal of the hopper assembly 24 from its operative position of close proximity and register with the casing section 70 in the manner previously described, or due to removal of the capstan wrench '64 from its retracted position adjacent the side member 356 of the box-like casting 310, one or the other of the series-arranged pairs of contacts C1 or C2 will become open, thus opening the previously described motor circuit and deenergizing the motor and terminating the operation of the apparatus.

From the above description, it is thought that the operation and many advantages of the herein described comminuting apparatus will have become sufiiciently well understood that only a brief rsum of the operation of the apparatus as a whole need be set forth. The product which is fed to the hopper assembly 24 is usually preworked in a suitable grinder so that it enters the hopper assembly in a rough emulsion state. It is prevented from swirling within the hopper by means of the veins 273 which are cast in the metal of the throat 100. Any particles or lumps of gristle such as veins, sinews, tendons, small pieces of bone and the like which may be present in the product entering the chamber 34 from the hopper assembly 24 are broken up by the cooperation of the gristle-breaking or shearing lugs 227 with the end surfaces 225 of the knife-supporting arms 218.

The leading edges 228 of the blade-supporting arms 21% advance in rotary fashion through the product within the chamber 34 and perform a certain amount of product severing. The inclined faces Z22 exert an impelling action on the product as the arms 218 penetrate the latter and the product is forced toward the shear plate where it creates a region of relatively high pressure in the immediate vicinity of the plate. The shearing edges 232 of the knife blades proper 23b cooperate with the perforations in t he shear plate 52 and the product readily passes through the perforations due to the pressure differential on opposite sides of the plate. The magnitude of this pressure differential is enhanced by the creation of a partial vacuum or low pressure region within the chamber 34 in the vicinity of the impeller 56, such low pressure region exist 1 ,cial application of the invention.

.17 ing by virtue of the centrifugal expelling action of the im peller56. Thecomminuted material issuing from the impeller blades is forced through the opening 249 and into the composite sectional discharge conduit 40. The upper 'end of the discharge conduit is turned downwardly 'as at '416 to facilitate discharge of the comminuted material into a suitable receptacle. p

While one'specific and preferred form of the comminuting, apparatus has been illustrated and described herein, it will be understood that this form does not by any means indicate the only form contemplated The form illustrated is only one which has been developed for commer The invention therefore is not to be limited to the precise arrangement of partsshown in. the accompanying drawings or described in thisfspecification since various changes in the details of construction may be resorted to withoutdeparting the spirit of the invention. Forexample, while inthe accompanying drawings and through- ..Out this specification the composite housing assembly 70, .72, and consequently the generally cylindrical comminuting chamber 34 enclosed thereby has been illustrated and described as having its central axis extending horizontally, it is obvious that the proper functioning of the various comminuting instrumentalities within the chamberwill not be impaired by otherwise positioning the housing assembly.

If such assembly be positioned so that its central axis extends vertically, the character of the feed hopper may be altered so that the raw food products are fed vertically downwardly into the rim of the comminuting chamber and, in such an instance, this upper rim of the chamber may, for purposes of claim terminology herein be regarded as the forward rim of the chamber with the herein stated forward and rearward directions of the product feed being regarded as upward and downward directions of feed respectively. Only insofar as the invention has particularly been pointed out in'the accompanying claims is the same to be limited.

We claim:

, 1. In an apparatus for comminuting food products, in combination, a base plate, a generally cylindrical housling fixedly mounted on said base plate and having its central axis extending horizontally, said housing defining at least in part an internal comminuting chamber and be- :ing provided with a rim through which the front end of the chamber communicates with the atmosphere, com minuting ,instrumentalities operatively disposed in said chamber, a feed hopper axially slidable on said base plate longitudinally of the housing toward and away from the latter, said hopper having a throat portion presenting a rim re-gion'in axial alignment with said rim of the housing, means on said base plate supporting said hopper for sliding movement along the base plate between a rejtracted position wherein said throat rim is remote from said rim of the housing and an advanced position wherein it is in coextensive contact. therewith, and manuallyoperated means mounted on said base plate and operably connected to said hopper for sliding said hopper between its advanced and retracted positions.

2. In an apparatus for comminuting food products, a

base plate, a generally cylindrical housing fixedly' mounted on said base plate and having its central axis extending horizontally, said housing defining at least in part an internal comminuting chamber and being provided with an open rim through which the front end of the chamber communicates with the atmosphere, comminuting instrumentalities including a drive shaft operativelydisposed in said chamber, a feed hopper axially slidable on said base plate longitudinally of the-housing toward and away from the latter, said hopper having a throat portion presenting a rim region in axial alignment with the open rim of the housing, said hopper being movable between a retracted position wherein said throat rim is remote from the open rim of the housing and an advanced position wherein it is in operative register and amass};

7, 3. In an apparatus for comminuting food products, a

base] plate, a generally cylindrical housing fixedly mounted'onsaid base plate andh-aving its central axis extending horizontally, said housing defining at least in part an internal comminuting chamber and being provided with an open rim, through which the end of the chamber. :on 1'rnunicates with the atmosphere, comminuting in'str umen talities including a drive shaft operatively disposed in said comminuting (chamber, a feed hopper axially slidable on said .base plate longitudinally of the housing toward and away from the latter, said hopper having -athroat portion presentinga rim region in axial aligment with the open rim of the housing, said hopper bein'g moyable between ,a retracted position wherein its rim is remote from the rim of the housing and an advanced position wherein it is in operative register and engagement therewith, an electric motor operatively connected to said drive shaft in driving relationship, an electric circuit for energizing said motor including a switch assemblyinclud-ing a pair of normally open contacts, a thrust rod mounted, for axial sliding movement in a direction longi-tud inal-ly of the housing, an end of said thrust rod being positioned in the path of movement of thehopper and being engageable with the hopper as the latter approaches its advanced position and adapted .to he shifted thereby, the other end of said thrust rod being engag'eaible with said switch assemblyand operable to close its contacts upon such shifting of the thrust rod. .4, In an apparatus for comminuting food products, in combination, a housing presenting an inner wall surface defining, at least in part, a comminuting chamber, a substantially flat, perforate shear plate extending transversely of the chamber and dividing the same into a product-receiving. compartment and a product discharge compartment, a rotary drive shaft. projecting into said housing centrally and longitudinally of the chamber, a cutter as- .sembly mounted on an end of the drive shaft for rotation in unison therewith and having a plunality of arms operable within the product-receiving chamber and carrying cutter elements adapted to sweep around the adjacent face of the shear plate in shearing relationship, means yieldingly urging said cutter assembly against said shear plate, and a backing spiderfor applying uniform support to said shear plate, said spider extending transversely of the chamber within the product discharge compartment, and having an inner hub portion, an outer rim portion, and a series of intervening spider spokes for uniform support of said shear plate, said wall surface of the housing being formed with a shoulder engageable with the outer rim portion of the spider for limiting movement of the latter, said cutter assembly normally urging said shear plate against said backing spider, one side of said spider presenting a substantially planar bearing surface for the adjacent face of said shear plate. I

'5. In an apparatus for comminuting food products, according to claim 4, wherein said shear plate is formed with a central opening, said cutter assembly having a central hub extending through said opening and being connected to the drive shaft on the other side of said shear plate, the clearance between said central hub and said central opening in the shear plate being relatively small, that is in the order of .005 inch as a minimum and not substantially greater than .015 inch. I 6. ln'an apparatus for comminuting food products, in combination, a housing presenting an inner wall surface defining, at least in part, a comminuting chamber, a sub. stantially flat, perforate shear plate extending transversely of the chamber and dividing the same into a product-receiving compartment and a product-discharge compartment, a rotary drive shaft projecting into said housing centrally and longitudinally of the chamber, a cutter assembly mounted on an end of the drive shaft for rotation in unison therewith and having a plurality of arms operable within the product-receiving chamber and carrying cutter elements adapted to sweep around the adjacent face of the shear plate in shearing relationship, means yieldingly urging said cutter assembly against said shear plate, and a backing spider for applying uniform support to said shear plate, said spider extending transversely of the chamber within the product discharge compartment, having an inner hub portion, an outer rim portion, and a series of intervening spider spokes, said wall surface of the housing being formed with a forwardly facing shoulder engageable with the rim portion of the spider for limiting rearward movement of the latter, said cutter assembly normally urging said shear plate against said backing spider, said hub and rim portions of the spider and said spider spokes, each being of forwardly tapering cross section in the direction of travel of the product to enhance the passage of the product issuing from said perforate shear plate through the spider, said spider presenting a substantially planar bearing surface for the rear face of said shear plate whereby the inner hub portion of the spider bears against and supports the central region of the shear plate, and the outer rim portion of the spider bears against and supports the outer peripheral region of the shear plate, while the radially extending spokes of the spider bear against the intervening region of the shear plate for uniform support of said shear plate. a

7. In a rotary product comminuting apparatus, the combination with a perforate shear plate, of a backing spider for applying uniform support to said shear plate, said backing spider having a hub portion in register with the central region of the shear plate, an outer rim portion in register with the outer peripheral region of the shear plate, and a series of intervening spokes extending radially between the hub and rim portions for uniform support of said shear plate, said radial spokes in combination with the hub and peripheral portions of the spider defining a series of circumferentially spaced trapezoidal openings through which the product issuing from said perforate shear plate is adapted to pass, the surrounding walls of said openings being provided with bevelled surfaces to facilitate passage of the product through the spider.

8. In an apparatus for comminuting food products, in combination, a housing defining at least in part an internal generally cylindrical comminuting chamber the axis of which extends horizontally, said housing being provided with a circular rim through which the front end of the chamber communicates with the atmosphere, comminuting instrumentalities operable within the chamber upon raw food products introduced into the chamber through said rim, a feed hopper for said comminuting chamber comprising an upper hopper section proper and a lower throat section establishing communication between the hopper section and the circular rim of the comminuting chamber, said hopper section presenting a smooth inside funnel-like surface of inverted frustroconical configuration, the small base of said inverted frustro-conical surface being circular, said throat section presenting an internal smooth surface having an upper circular rim in register and communication with said small base of the frustro-conical surface of the hopper section and a lower circular rim in register and communication with said circular rim of the comminuting chamber and said small base and said lower circular rim being in transverse planes, said upper circular rim of said throat portion being of the same inner diameter as the inner diameter of the small base and said throat section extending smoothly downwardly and rearwardly towards the rim of the housing to form a smooth. continuation of the inner funnel like surface of the hopper.

9. In an apparatus for comminuting food products, the combination set forth in claim 8 wherein the intermediate reaches of said internal surface of the throat section are circular in both vertical and horizontal cross section near the respective ends thereof.

10. Apparatus according to claim 8 wherein said housing rim and said lower rim lie in a vertical plane.

11. In an apparatus for comminuting food products, the combination set forth in claim 10 wherein the small base of said inverted frustro-conical surface of the hopper section is displaced forwardly of and above the vertical plane of the rim of the comminuting chamber and wherein the central axis of said internal surface of the throat section is inclined from the horizontal.

12. In an apparatus for comminuting food products, the combination set forth in claim 10 wherein the small base of said inverted frustro-conical surface of the hopper section is displaced forwardly of the vertical plane of the rim of said comminuting chamber, wherein the cen tral axis of said internal surface of the throat section is inclined from the horizontal, the inside surfaces of said upper hopper section and lower throat section presenting a smooth continuous unbroken substantially straight linear stretch extending from the lowermost point on the lower vertical rim of the internal surface of the throat section to the foremost point on the large base of the internal surface of the hopper section.

13. In an apparatus for comminuting food products, the combination set forth in claim 12 including, additionally, a plurality of elongated straight ribs formed internaliy of the throat section on said internal surface thereof adjacent the bottom thereof in the general direction of product flow through said throat section.

14. In an apparatus for comminuting food products, a base plate, a generally cylindrical housing fixedly mounted on said base plate and having its central axis extending horizontally, said housing defining at least in part an internal comminuting chamber and being provided with an open rim through which the front end of the chamber communicates with the atmosphere, comrn'nuting instrumentalities including a drive shaft operatively disposed in said chamber, a feed hopper axially slidable on said base plate longitudinally of the housing toward and away from the latter, said hopper having a throat portion presenting a rim region in axial alignment with the open rim of the housing, means on said base plate supporting said hopper for sliding movement along the base plate between a retracted position wherein said throat rim is remote from the open rim of the housing and an advanced position wherein it is in operative register and engagement therewith, a motor for driving said drive shaft and operatively connected thereto, and means automatically operated when the hopper is moved away from its advanced position for preventing said motor from driving said shaft.

15. In an apparatus for comminuting food products, in combination, a housing presenting an inner wall surface defining, at least in part, a comminuting chamber, a substantially fiat, perforate shear plate extending trans versely of the chamber and dividing the same into a product-receiving compartment and a product discharged compartment, a rotary drive shaft projecting into said housing centrally and longitudinally of the chamber, a cutter assembly mounted on an end of the drive shaft for rotation in unison therewith and having a plurality of arms operable within the product-receiving chamber and carrying cutter elements adapted to sweep around the adjacent face of the shear plate in shearing relationship, and a backing spider for applying uniform support to said shear plate, said spider extending transversely of the chamber within the product discharge compartment and having an inner hub portion, an outer rim portion, and

. a series of intervening spider spokes for uniform support of said shear plate, one side of said spider presenting a substantially planar bearing surface for the adjacent face of said shear plate, and means for limiting movement of the spider relative to the housing.

16. In an apparatus for comminuting food products, according to claim 15, wherein said shear plate is formed with a central opening, said cutter assembly having a central hub extending through said opening and being connected to the drive shaft on the other side of said shear plate, the clearance between said central hub and said central opening in the shear plate being relatively small, that is in the order of .005 inch as a minimum and not substantially greater than .015 inch.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN AN APPARATUS FOR COMMINUTING FOOD PRODUCTS, IN COMBINATION, A BASE PLATE, A GENERALLY CYLINDRICAL HOUSING FIXEDLY MOUNTED ON SAID BASE PLATE AND HAVING ITS CENTRAL AXIS EXTENDING HORIZONTALLY, SAID HOUSING DEFINING AT LEAST IN PART AN INTERNAL COMMINUTING CHAMBER AND BEING PROVIDED WITH A RIM THROUGH WHICH THE FRONT END OF THE CHAMBER COMMUNICATES WITH THE ATMOSPHERE, COMMINUTING INSTRUMENTALITIES OPERATIVELY DISPOSED IN SAID CHAMBER, A FEED HOPPER AXIALLY SLIDABLE ON SAID BASE PLATE LONGITUDINALLY OF THE HOUSING TOWARD AND AWAY FROM THE LATTER, SAID HOPPER HAVING A THROAT PORTION PRESENTING A RIM REGION IN AXIAL ALIGNMENT WITH SAID RIM OF THE HOUSING, MEANS ON SAID BASE PLATE SUPPORTING SAID HOPPER FOR SLIDING MOVEMENT ALONG THE BASE PLATE BETWEEN A RETRACTED POSITION WHEREIN SAID THROAT RIM IS REMOTE FROM SAID RIM OF THE HOUSING AND AN ADVANCED POSITION WHEREIN IT IS IN COEXTENSIVE CONTACT THEREWITH, AND MANUALLY OPERATED MEANS MOUNTED ON SAID BASE PLATE AND OPERABLY CONNECTED TO SAID HOPPER FOR SLIDING SAID HOPPER BETWEEN ITS ADVANCED AND RETRACTED POSITIONS. 